# Question #ccda2

May 20, 2017

I tried this:

#### Explanation:

We can use Newton's Second LAw and write:

$F = m a$

and from Kinematics:

$a = \frac{{v}_{f} - {v}_{i}}{t}$

or in numbers:

$F = 1200 \cdot \frac{27.78 - 0}{12} = 2778 N$

The friction opposes the motion in a way that you need more force to get the same acceleration.

So, in our case the car needs to produce an extra:

$3000 - 2778 = 222 N$ to overcome friction which will exactly be:

$222 N$